Power module for envelope tracking

Abstract

A power module at least includes an ET (Envelope Tracking) module. The ET module includes a buck converter, an inductor, and a capacitor. The buck converter is coupled to a work voltage. The buck converter has a first input terminal for receiving a first control signal, a second input terminal coupled to a supply node, and a buck output terminal The inductor is coupled between the buck output terminal of the buck converter and the supply node. The capacitor is coupled between the supply node and a ground voltage. The ET module is configured to supply a first adaptive supply voltage at the supply node. The first adaptive supply voltage is determined according to the first control signal.

What is claimed is: 
     
       1. A power module, comprising:
 an ET (Envelope Tracking) module, comprising: 
 a buck converter, coupled to a work voltage, wherein the buck converter has a first input terminal for receiving a first control signal, a second input terminal coupled to a supply node, and a buck output terminal; 
 an inductor, coupled between the buck output terminal of the buck converter and the supply node; and 
 a capacitor, coupled between the supply node and a ground voltage; 
 wherein the ET module is configured to supply a first adaptive supply voltage at the supply node, and the first adaptive supply voltage is determined according to the first control signal; 
 wherein the power module further comprises: 
 a mapping circuit, receiving a baseband signal, and generating the first control signal according to the baseband signal; 
 wherein the mapping circuit obtains information of I/Q channel magnitude from the baseband signal. 
 
     
     
       2. The power module as claimed in  claim 1 , further comprising:
 a baseband circuit, generating the baseband signal. 
 
     
     
       3. The power module as claimed in  claim 2 , further comprising:
 a power amplifier, coupled to the baseband circuit, wherein the power amplifier is supplied at the supply node by the ET module. 
 
     
     
       4. The power module as claimed in  claim 3 , further comprising:
 a local oscillator, generating an oscillation signal; and 
 a mixer, generating a mixing signal according to the baseband signal and the oscillation signal, 
 wherein the power amplifier is configured to amplify the mixing signal so as to output an RF (Radio Frequency) signal. 
 
     
     
       5. The power module as claimed in  claim 4 , wherein the first adaptive supply voltage substantially tracks an envelope of the RF signal. 
     
     
       6. The power module as claimed in  claim 5 , wherein the first adaptive supply voltage is a fixed value which is equal to or higher than a peak value of the RF signal. 
     
     
       7. The power module as claimed in  claim 5 , wherein a waveform of the first adaptive supply voltage comprises a plurality of dynamic slot windows, and a combination of the dynamic slot windows forms a shape which is similar to an envelope of the RF signal. 
     
     
       8. The power module as claimed in  claim 5 , wherein the relationship between the first adaptive supply voltage and the RF signal is as follows:
   ET_BW×RR=RBET_BW
 
 wherein ET —  BW represents a signal bandwidth of the RF signal, RR represents a reduced rate, and RBET_BW represents a signal bandwidth of the first adaptive supply voltage. 
 
     
     
       9. The power module as claimed in  claim 8 , wherein the reduced rate is less than 1 and greater than or equal to 0.